The invention is concerned with a motor vehicle door with a multi-shell door body which includes pane guides for a lowerable door window pane and a removable anti-ram trim as a lower wall portion.
Such a motor vehicle door is described in German Patent (DE-PS) No. 3,425,776. The basic supporting structure of the door body of this motor vehicle door consists of an inner wall, lateral door end walls and a door bottom which, formed from sheet metal, are welded to one another. An outer wall of the door body connected releasably to the basic structure is intended to be utilized as far as possible to improve the design strength of the door body. However, this can be guaranteed completely only when the two portions of the longitudinally divided outer wall consist of metal sheets, the elasticity behavior of which corresponds approximately to that of the sheets of the basic structure. Since the two portions are connected to one another along their common joining line in a tension-resistant manner by means of an annular bearer arranged in the door interior, the door body, when subjected to impact stress in the event of a collision, exhibits a deformation behavior which is closely comparable to that of conventionally used two-shell motor vehicle doors with a continuous outer wall.
However, the deformation behavior shows a pronounced change when the lower portion of the outer wall is formed by an anti-ram trim, as is likewise provided according to the above-mentioned publication.
In accordance with the intended use of anti-ram trims, their elasticity behavior must be such that, after deformation as a result of light ramming shocks, such as often occur during parking maneuvers, they spring back into their initial form again. They therefore consist of hard elastic plastics.
Because of their deformation behavior, anti-ram trims are therefore unsuitable for making an adequate contribution to increasing the design strength of the door body. This deficiency is mitigated somewhat in the known door design because the door body is stiffened in the transverse direction of the door by means of the annular bearer, since at least the upper half of the door thereby has the desired deformation behavior. Nevertheless, the pane shaft provided in the annular bearer has to be provided with a clear excess width, so that the customary mounting of the pane guides, in which these are pushed into the door body from above, can be preserved. The result of this is that a cross section with a high moment of resistance has to be chosen for the annular bearer, so that this can span the clear width in the desired way. Consequently, the annular bearer acquires the nature of a door stiffener comparable to reinforcing sections which are used to increase the lateral impact strength. However, on the other hand, in door bodies with an outer wall divided approximately into two halves there is not the best possible height arrangement for such a reinforcing section, since this should be integrated in the door body most approximately somewhat above conventional bumper heights of motor vehicles. If, in addition to the annular bearer, a reinforcing section underneath the latter were to be used, it would be supported precisely on the supporting structure located in the lower door portion and having only low design strength. It would also be difficult to make a connecting junction between the ends of the reinforcing section and the end faces of the door body.
For the reasons explained, an object of the invention is to develop further a motor vehicle door of the relevant generic type, to the effect that, while ensuring the least possible use of material, it can guarantee a clearly improved supporting behavior under impact stress in the event of a collision.
According to the invention, this object is achieved by a door construction wherein the transverse reinforcement is formed by a transverse wall with a pane shaft matched to the passage width of the pane guides, wherein the transverse wall merges into an intermediate wall extending downwards relative to the door between the inner wall (inside the door panel) and the plane of the pane guides, and wherein the transverse wall is connected to the bottom of the door body via the intermediate wall. In the construction of especially preferred embodiments of the invention, there is formed a supporting wall which extends over the entire door height of the door body and which is connected to the inside door pane via the two door end walls and the door bottom to form a common basic supporting structure of the door body.
Since the pane shaft in the transverse wall takes the form of only a narrow slit, a simple sheet metal wall is sufficient as a transverse reinforcing section.
Preferably, the upper wall portion, the transverse wall and the intermediate wall are designed as a one piece deep drawn article, as a result of which they can be welded continuously to the connecting sheets and require no separate connection to one another.
If a height offset for a sill catch is provided in the bottom of the door body according to certain preferred embodiments, the portion of hook-shaped profile of the door bottom should be formed by a downwardly projecting edge portion of the intermediate wall. As a result, the sill catch remains effective under the influence of the deforming intermediate wall even if a welding seam between an approximately horizontal portion of the door bottom and the intermediate wall were to break.
To improve passenger safety in collisions even further according to certain preferred embodiments, there is arranged additionally between the pane guides and the anti-ram trim of the door body a reinforcing section which is supported on the intermediate wall in the direction of the depth of the door body. Preferably, the reinforcing section is formed by a U-shaped bar of tubular cross section, of which the ends, engaging around the lower plane between the pane guides, are angled at 90.degree.. The advantage of a closed wall tube cross section is a high bending resistance and at the same time a low dead weight. The tubular bar can easily be fastened, when the anti-ram trim is removed, by means of screw flanges welded on the end face, since these are readily accessible from outside.
To make it easier to install the pane guides, they can be combined with the reinforcing section to form an assembly unit according to certain preferred embodiments. For mounting, with visual checking the assembly unit can be pushed upwards through the narrow pane shaft, with the guide rails in front, until the installation position of the reinforcing section is reached. Thus, as a result of the operation of screwing on the reinforcing section, at the same time the guide rails are fastened in the door body. It is also advantageous if the entire adjusting mechanism for the guide rails and the associated lifting mechanism, together with the drive motor, are locked with the assembly unit. All the necessary operations for adjusting the pane guides are thereby possible from the easily accessible installation space, this saving time both during initial assembly and in maintenance work.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.